folders and pages which were not set as default pages don't have 'is_default_page' property.

https://github.com/plone/plone.app.multilingual/commit/d72df172dff861f962321caa381adf22b3cd4613
Revert translation: display of default pages of folders (it doesn't show content which doesn't have 'is_default_page' attributes).  [bogdangi]
Fix test
Merge pull request #77 from bogdangi/master

Revert translation: display of default pages of folders